Swivel chair action



Feb. 23, 1943.

Filed Aug. 3, 1942 Patented Feb. 23, 1943 SWIVEL CHAIR ACTION Albert M.Schaaf, Jasper, Ind., assignor to New Indiana Chair Company, acorporation of Indiana Application August 3, 1942, Serial No. 453,351

1 Claim.

This invention relates to tilting swivel chair actions, and moreparticularly to a chair action which does not require the use of aspring.

The primary object of the invention is to provide a simple, comfortableand inexpensive action for a swivel chair which will permit the seat andback portion to be tilted backwardly at will without danger ofupsetting.

Most of the tilting swivel chair actions now in use are made of steeland iron and employ strong tension springs to oppose the backwardtilting movement. It is difficult to avoid noisy squeaks when the chairis operated and occasionally an extended spring will snap and throw apiece of metal away from the chair in a way that may injure the user. Inthe present invention, the transverse pivot is so disposed that nosprings are necessary and this danger is eliminated.

Another object of the invention is to provide a smooth pivot post whichhas a simple vertically adjustable thrust bearing and does not requirescrew threads for its adjustment.

The invention is illustrated in a preferred embodiment in theaccompanying drawing, in which- Figure 1 is an elevational view of acomplete chair embodying the invention; Figure 2, a sectional view ofthe bottom of the chair, taken as indicated at line 2 of Figure l; andFigure 3, a fragmentary sectional view, taken as indicated at line 3 ofFigure 2.

In the embodiment illustrated, the chair has the usual supporting base 4which may be mounted on casters 5, and by means of the improved action,supports the chair seat 6 provided with a back rest l. The base has ahollow vertically extending bore, preferably provided at its top with abearing washer 8.

A pivot post 9 may be made of Wood or other suitable material and isprovided with Several holes IIJ adapted to be impaled by a bolt II tomake a collar shaped thrust bearing I2 vertically adjustable.Preferably, the underside of the thrust bearing is provided withanti-friction domes I3.

A supporting block I4 is rigidly 'secured to the top of the post and hasa top, forwardly extending, flat, horizontal face I5 adapted to engagethe bottom of the chair seat 6 when the chair is in normal uprightposition. The block also has a rearwardly inclined face I6 adapted toengage the rear portion of the chair seat when it is tilted backwardly.The chair seat is provided with a pair of downwardly extending bars I'Iwhich iiank the supporting block I4 and are pivotally connected theretoby means of a transverse pivot I8. It will be noted that the pivot I8 isdisposed well back of the pivot post 9 and slightly in rear of thecenter of gravity of the chair seat and back rest.

The horizontal face I5 and the inclined face I6 meet at a line above andslightly in rear of the center of the pivot I8. This arrangement willcause the chair normally to assume the upright position. However, when aperson is seated in the chair, it may readily be tilted backwardly to adesired position, limited by the inclined face I 6. The rearwardlyinclined position of the chair seat and back is indicated by dottedlines in Figure 3.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom for some modifications will be obvious to those skilled in theart.

I claim:

In a swivel chair having a base, seat and back rest, a tilting actioncomprising: a vertical pivot post journalled in the base and provided atits top with a rigidly mounted supporting block; and a. transverse pivotbetween the supporting block and chair seat disposed back of the centerof gravity of the seat and back rest so that the chair will normallyassume an upright position without the aid of springs, said supportingblock having a. top front portion extending in front of the pivot postto engage the bottom face of the chair seat, when the chair is in itsnormal upright position, and having a depressed rear portion, back ofthe transverse pivot, to engage the bottom face of the chair seat andlimit its backward tilting movement.

ALBERT M. lSCHAAF.

